Why did Riot remove ranked 5's?

When the beginning of the season came I was super pumped, the marksman updates, the rotating game modes, group ranked! But there's one change I'm still sad about, which is the removal of ranked 5's. I understand that you can play with your friends in norms and dynamic queues, but I'm plat 1, and one of my best friends is unranked, and I miss the feeling of playing in a competitive enviroment with him. Yes there was alot of high ranking teams, but I didn't mind it, I've had times we've destroyed teams with diamond players (trust me, it was the best feeling in the world), But now it just feels I'm forced to make a smurf if I want to play with them in serious enviroment, which has a different feel then Ranked 5's. I understand it's too late in the season to make any changes, but I want to know why you had to take it down, and why you decided to keep ranked 3's, which is much less popular. It honestly just makes me sad I can never have that dynamic in anymore games, especially after commiting to a name change.